The cost of feeding an animal is estimated to be approximately 70% of the total cost of the production of that animal. Therefore, ways to decrease these feeding costs can have a very important effect on the final cost of animal products, such as meat, milk, eggs and wool.
Animals use the energy extracted from the feed for different purposes. A principal purpose is referred to as “maintenance”. The energy for maintenance is used by the animals to maintain life. If the feed does not provide enough energy for maintenance, animals lose weight as they have to use their body reserves to survive. Once maintenance requirements have been met, the rest of the energy can be used for growth (for example, meat, milk, eggs and wool) or reproduction.
There are two classical ways to increase the amount of energy that animals are able to extract from feed and, therefore, to improve their energy and/or feed efficiency. One is to increase the energy in the feed, and the other is to change the energy metabolism of the animal to make their metabolism more efficient.
Enzymes increase the energy of the feed. The idea behind the use of enzymes is that enzymes degrade compounds that are undigestible or have antinutritional properties. This degradation allows the animal to extract more energy from the feed. Typical examples of enzymes are pentosanases, beta-glucanases or phytases used to degrade pentosans (found in wheat), beta-glucans (found in barley) or phytates (found in vegetable ingredients), respectively.
Antibiotics change the way energy is used by the animal. The exact way that antibiotics increase the energy available for the animal is not clearly understood. However, antibiotics have been related to a decrease in the amount of energy needed by the animal to fight pathogens. Antibiotics would keep the microbial challenge low and, as a result, less energy would be allocated to the immune system to fight those pathogens. This savings in energy can then be used for production. Therefore, antibiotics would not increase the energy density of the feed, but would decrease the maintenance requirements of the animal, with the net result being more energy available for production.
New regulatory measures are constraining the use of antibiotics as growth promoters in many countries. In 2006, the European Union forbade the use of antibiotics as growth promoters, and the FDA is studying limitations on the use of antibiotics in the U.S.
Hormones are examples of other products that change the way energy is used by animals by changing where that energy is directed. For example, the hormone somatotropin increases the amount of energy allocated to milk production instead of meat production. The hormone ractopamine increases the amount of lean tissue which correspondingly decreases the amount of fat tissue.
The use of hormones and antibiotics in animal production is facing a strong opposition by public opinion due to possible residues of these materials in animal products. Therefore, products that could improve feed and energy efficiency that are not hormones or antibiotics have a very attractive market.
U.S. Patent Application Publication No. US 2008/0226760 discloses a composition which is useful in the process of this invention. However, that composition is disclosed as having antimicrobial activity; that is, for animals that show clinical signs of disease or other microbial challenge.
In the process of this invention, the composition disclosed in U.S. Patent Application Publication No. US 2008/0226760 is shown to improve feed efficiency for animals kept in situations free of disease or other microbial challenge. Therefore, the improved feed efficiency results from a change in the use of energy from feed, not from a decrease in the microbial challenge.
The present invention shows that the improved energy efficiency of animals treated with this composition occurs when the animals are kept in situations free of disease or other microbial challenge. Therefore, the improved energy efficiency is not caused by the decrease in microbial challenge or the lower amount of energy used by the immune system, but by changes in the use of energy. Thus, in the present invention, a process has been developed:                to improve the energy efficiency of animals;        to improve the carcass characteristics of animals;        to decrease the cost of feeding animals;        to not leave residues in the meat, milk, eggs, wool or other products of animals.        